A locking ball landing collar has been used as a blanking collar in liner applications to permanently block the flow path at the toe of a liner system. As shown in FIG. 1, for example, a system 20 is shown having a rig 22, a pump system 24, and a liner system 30. The liner system 30 includes a liner top packer 32 coupled to a liner hanger 34 from which the liner 36 extends. A landing collar 50 with a ball seat is coupled to the liner 36. Further downhole, the liner 36 includes a float collar 40 and a float shoe 42. The liner system 30 is run and set in the wellbore 10 with a running tool (not shown) and known procedures. The collar 50 is installed in conjunction with the standard float equipment 40, 42 and provides a primary barrier between the inner dimension of the liner 36 and the formation so liner accessories can be hydraulically activated.
FIG. 2 illustrates a partial cross-sectional view of a locking ball landing collar 50 according to the prior art for use with a liner system (e.g., 30 in FIG. 1). As shown, the collar 50 includes a body 52 in which a housing 54 affixes. The body 52 has box and pin connections 53a-b for threading onto sections of tubing, such as a liner (not shown). A sleeve 56 is movably disposed in the housing 54 and is temporarily held by shear screws 60 in an open condition relative to windows 62 on the housing 54.
A body lock ring 58 can be disposed between the sleeve 56 and the interior 55 of the housing 54 to lock the sleeve 56 in a closed condition once moved downward to shear the screws 60. A ratchet surface defined in the housing's interior 55 can engage the body lock ring 58 to hold the sleeve 56 closed. A stud 64 disposed on the end of the housing 54 has an external seal 66 to seal against the inside 57 of the sleeve 56. This closes off fluid communication through the housing's windows 62 so that the collar 50 can close off fluid communication.
During installation, the collar 50 is open and allows fluid flow through the liner (36: FIG. 1). When the liner and accessories need to be set, a setting ball (not shown) is circulated into a seat 59 of the collar's sleeve 56. The application of internal pressure in the liner (36) then shears the collar's sleeve 56 closed and permanently blocks the flow path through the liner (36). This blocked flow path allows the liner system (30) and other accessories to be pressure cycled and hydraulically set.
When set, for example, the collar 50 isolates pressure above it, after circulation, in order to actuate other hydraulic components in the liner system. Pressure integrity is maintained if the ball rolls off the ball seat 59 in horizontal conditions. The collar 50 has been used in cemented and uncemented liner installations where hydraulically actuated accessories are installed.
The collar has also been used in multi-zone open hole completions. The collar is ran into the well above the float equipment and below open hole packers used for multi-zone isolation. Landing a ball into the collar then allows for pressure isolation in the liner to set the hydraulic packers.
The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.